Touch/display driving circuit and device including same

ABSTRACT

A power circuit according to the present disclosure may include a multiplexer connected to a first power line and a second power line and selecting and outputting one of a first voltage supplied through the first power line and a second voltage supplied through the second power line. Further, the power circuit may include a first power circuit which generates a first driving voltage and a second driving voltage by using a voltage supplied from the multiplexer, recognizes whether there is the first voltage supplied through the first power line, and does not output the first driving voltage when the first voltage is not recognized.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/830,945, filed on Jun. 2, 2022, which claims priority fromRepublic of Korea Patent Application No. 10-2021-0082796, filed on Jun.25, 2021, which are hereby incorporated by reference in their entirety.

BACKGROUND 1. Field of Technology

The present disclosure relates to a touch/display driving circuit and adevice including the same.

2. Description of the Prior Art

Display devices configured to enable touch inputs on display screens(for example, touch/display devices) are applied to various electronicdevices.

Touch/display devices may have touch panels attached to display panels(on-cell type), or may have touch electrodes embedded in display panels(in-cell type), thereby implementing various types of touch and display.

Some of common electrodes of a touch/display device may be used as touchelectrodes so as to simultaneously implement touch and display within asingle device. A single time interval may be time-divided into a displaydriving interval for transmitting image data to common electrodes and atouch driving interval for transmitting a touch driving signal to touchelectrodes, thereby adjusting the operating cycle of touch and display.

In order to reduce power consumed by a display device, power needs to besupplied differently during a time interval for display to be performedby the display device and a time interval for touch driving. When thedisplay device performs a display operation, power for touch sensing isconsumed together. Furthermore, when the display device performs a touchsensing operation, power for display is consumed together. Accordingly,power consumed by the panel increases absent adjustment of powersupplied regardless of the kind of operation of the display device.

Even if power for display driving and power for touch driving isseparately supplied in the case of a display device, and if power fortouch sensing is solely supplied without distinguishing between acircuit for touch driving and a circuit for display driving, the circuitfor display driving may fail to operate correctly. A touch sensingcircuit designed to enable both touch driving and display driving needsto be supplied with power stably regardless of the time-divided interval(display interval and touch interval).

SUMMARY OF THE INVENTION

In view of the above-mentioned background, it is an aspect of thepresent disclosure to provide a touch/display driving circuit capable ofperforming a display operation and a touch operation stably regardlessof the type of input power, and a device including the same.

In accordance with an aspect, the present disclosure may provide a powercircuit including: a multiplexer connected to a first power line and asecond power line, and configured to select and output one of a firstvoltage supplied through the first power line or a second voltagesupplied through the second power line; and a first power circuitconfigured to generate a first driving voltage and a second drivingvoltage by using a voltage supplied from the multiplexer, recognizewhether there is the first voltage supplied through the first powerline, and not output the first driving voltage when the first voltage isnot recognized.

In accordance with another aspect, the present disclosure may provide atouch sensing circuit including: a multiplexer connected to a first lineto receive a main voltage and connected to a second line to receive asub-voltage; a power management circuit configured to receive onevoltage which the multiplexer selects and output from among the mainvoltage and the sub-voltage; and a touch modulation circuit connected tothe power management circuit to modulate a signal transferred to a touchelectrode, wherein the multiplexer is configured to change a type of avoltage selected based on a driving mode of a panel.

In accordance with another aspect, the present disclosure may provide atouch sensing circuit including: at least one buck converter configuredto convert an output voltage into a voltage having a lower level than aninput voltage; at least one power management circuit configured togenerate a voltage and transfer the voltage to a source readout circuitor a touch modulation circuit; and at least one multiplexer configuredto select one from among multiple types of input power and output theselected input power to the power management circuit, wherein the powermanagement circuit includes a power sensing line connected to one ofmultiple types of input power transferred to the multiplexer, and isconfigured to determine a type of input power, based on a signalreceived through the power sensing line.

As described above, according to the present disclosure, even if mainpower is not input in the case of a touch sensing circuit to which twokinds of power are input, sub-power may be used to maintain normaldriving of the touch operation.

In addition, the present disclosure may provide a touch function and adisplay function through a more simplified circuit configuration, andpower consumed by the panel and the touch sensing circuit may bereduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the configuration of a touch sensing circuitaccording to an embodiment of the present disclosure;

FIG. 2 illustrates, from the viewpoint of a power circuit, theconfiguration of a touch sensing circuit according to an embodiment ofthe present disclosure;

FIG. 3 is a first illustrative block diagram showing a signal flow of atouch sensing circuit according to an embodiment of the presentdisclosure;

FIG. 4 is a second illustrative block diagram showing a signal flow of atouch sensing circuit according to an embodiment of the presentdisclosure.

FIG. 5 is a timing diagram illustrating a change in input power of apower management IC according to an embodiment of the presentdisclosure;

FIG. 6 is a diagram illustrating a method for determining an operationmode of a panel according to an embodiment of the present disclosure;

FIG. 7 is a diagram illustrating a method for determining an operationof a power management IC according to an embodiment of the presentdisclosure; and

FIG. 8 is a diagram illustrating a method for dividing an operation modeof a panel according to an embodiment of the present disclosure;

FIG. 9 is a third illustrative block diagram showing a signal flow of atouch sensing circuit according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 illustrates the configuration of a touch sensing circuitaccording to an embodiment of the present disclosure.

Referring to FIG. 1 , the display device 100 may include a panel 110, asource readout IC (SRIC) 120, a touch modulation IC (TMIC) 121, amicrocontroller (MCU) 122, a power management IC (PMIC) 123, a gatedriving IC (GDIC) 130, a timing controller (TCON) 150, a host 160, etc.

Multiple data lines (DL) and multiple gate lines (GL) may be disposed inthe panel 110, and multiple pixels (P) may be disposed therein. A pixelmay include multiple sub-pixels (SP).

The panel 110 may include both a common electrode and a touch electrodeso as to perform a touch function and a display function, and the commonelectrode and the touch electrode may be disposed by dividing oneelectrode. The touch electrode may sense touching or approaching of anobject by using one among a mutual capacitance scheme and aself-capacitance scheme.

The source readout IC 120 may include a source driver IC (SDIC) therein.The source driver IC may supply data voltage to the sub-pixels (SP)through the data lines (DL). The data voltage supplied through the datalines (DL) may be supplied to the sub-pixels (SP) on the basis of a gatedriving signal.

Further, the source readout IC 120 may include a readout IC (ROIC)therein. The readout IC may be embedded in the source readout IC 120together with the source driver IC. The readout IC may transfer a touchdriving signal to a touch electrode around a sub-pixel (SP) through atouch line (TL), and may receive touch sensing data which is the amountof a signal change of the touch electrode.

The touch modulation IC 121 may receive an output voltage from the powermanagement IC 123, and may synchronize and modulate a voltagetransferred to the source readout IC 120 during a touch driving periodand a voltage transferred to a level shifter (not shown) connected tothe gate driving IC 130.

In order to reduce an effect which the parasitic capacitance of a touchsensor has on the sensing result, the touch modulation IC 121 maygenerate a zero load driving (ZLD) signal and transmit the same to apanel and the gate driving IC 130. The zero load driving (ZLD) signalmay have the same phase as a driving signal for driving the touchsensor. When the zero load driving (ZLD) signal is applied to a positiveelectrode of a parasitic capacitor together with a driving signal, theamount of electrical charge with which the parasitic capacitor ischarged becomes 0, and thus the parasitic capacitance may disappear.

The microcontroller 122 may be connected to the source readout IC 120 soas to transmit or receive data to or from the source readout IC 120. Themicrocontroller 122 may transmit data for controlling the source readoutIC 120 to the source readout IC 120. The source readout IC 120 may sensetouching or approaching of an external object from the touch sensor togenerate touch sensing data, and may transmit the touch sensing data tothe microcontroller 122. The microcontroller 122 may be defined as atouch microcontroller (Touch MCU (TMCU)) or a touch control circuit.

The microcontroller 122 and the source readout IC 120 may performcommunication on the basis of a serial peripheral interface (SPI) schemeor an inter-integrated circuit (I2C) scheme. In the SPI or I2C scheme,communication subjects may operate as a master or slave, wherein themicrocontroller 122 may operate as a master, and the source readout IC120 may operate as a slave.

The power management IC 123 may supply power to the panel 110, thesource readout IC 120, the touch modulation IC 121, the microcontroller122, the gate driving IC 130, and the timing controller 150. The powermanagement IC 123 may supply power to each circuit by transmitting adriving voltage thereto through a power line, and the voltage applied toeach circuit may be differently configured based on the characteristicsof the circuit. The power management IC 123 may function as a powersupply source for internal circuits of the display device 100.

The power management IC 123 may differently change and supply voltage,applied to each circuit, depending on the type of power input from thehost 160. The power management IC 123 may include at least one boostercircuit in order to increase output voltage, and may include at leastone buck circuit in order to reduce output voltage.

The gate driving IC 130 may supply a gate driving signal of a turn-onvoltage or a turn-off voltage through a gate line (GL). When a gatedriving signal of a turn-on voltage is supplied to a sub-pixel (SP), thesub-pixel (SP) is connected to a data line (DL). Further, when a gatedriving signal of a turn-off voltage is supplied to the sub-pixel (SP),the sub-pixel (SP) is disconnected from the data line (DL).

The timing controller 150 may receive image data, a timing signal, etc.from the host 160, and may supply a control signal to the gate drivingIC 130 and a touch control circuit. For example, the timing controller150 may transmit, to the gate driving IC 130, a gate control signal forstarting a scan. Further, the timing controller 150 may output imagedata (RGB) to the microcontroller 122. Further, the timing controller150 may transmit, to the microcontroller 122, a data control signal(DCS) which controls the source readout IC 120 to supply data voltage toeach sub-pixel (SP). Further, the timing controller 150 may transmit, tothe microcontroller 122, a touch control signal (TCS) which controls thesource readout IC 120 to drive a touch electrode of each sub-pixel (SP)such that the touch electrode senses a touch input.

The timing controller 150 may receive a touch synchronization signal(Touch Sync Signal) from the microcontroller 122, may divide a timeinterval in one frame into a display driving period and a touch drivingperiod, and may operate the source readout IC 120. The display drivingperiod may be a period for transferring data voltage to sub-pixels ofthe panel 110, and the touch driving period may be a period fortransferring touch driving voltage to sub-pixels of the panel 110.

The host 160 may supply at least one type of power to the powermanagement IC 123. The power management IC 123 may generate a drivingvoltage from power received from the host 160, and may supply thedriving voltage to the internal circuits of the display device 100, suchas the panel 110, the source readout IC 120, the microcontroller 122,the touch modulation IC 121, the gate driving IC 130, and the timingcontroller 150. Therefore, power which the host 160 supplies to thepower management IC 123 may be a source of power supplied by the powermanagement IC 123.

When the host 160 supplies power to the power management IC 123, thehost 160 may supply the power in two types of power which are main powerand sub-power. The main power may be power for a circuit which involvesin the display of the display device 100, and the sub-power may be powerfor a circuit which involves in touch sensing of the display device 100.The host 160 may provide each type of power in the form of voltage andcurrent. The main power may approximately have a main voltage (V_D) of5V and a display current of 2-3 A. The sub-power may approximately havea sub-voltage (V_T) of 5V and a touch current of 0.5 A or less. Powerconsumption in a display operation of the display device 100 is far morethan power consumption in a touch operation thereof, and thus, even whenvoltages have the same magnitude, a display current may be higher than atouch current.

The main power and the sub-power are provided in the form of voltage andcurrent, and thus, hereinafter, supply of the main power may bedescribed while being replaced with supply of a main voltage or supplyof a display current, and supply of the sub-power may be described whilebeing replaced with supply of sub-voltage or supply of touch current.However, the main power and the sub-power are not limited thereto.

The power management IC 123 may process power received from the host 160into a voltage and a current suitable for each circuit, and may supplythe processed power to each circuit. The main power may be processed soas to be supplied to a circuit, which involves in display, such as thetiming controller 150 or a gamma circuit, and the sub-power may beprocessed so as to be supplied to a circuit, which involves in touchsensing, such as the touch modulation IC 121 or the microcontroller 122.The main power and the sub-power are not limited thereto.

A signal level of a driving voltage, which the power management IC 123generates for display driving, and a signal level of a driving voltage,which the power management IC 123 generates for touch driving, may beadjusted to be different from each other. A target to which drivingvoltage generated by the power management IC 123 is transferred may alsobe changed depending on each driving mode. For example, an operation ofthe power management IC 123 may be controlled through an internalcontrol device (not shown), or may be controlled by a control signaltransferred from the microcontroller 122. The power management IC 123may select whether to control an operation, based on a reference settingvalue stored in an internal memory.

In the display device 100, all or some circuit elements for performing atouch operation and a display operation may be defined as a touchsensing circuit, and a circuit element for receiving power and providingpower to the inside of the display device 100 may be defined as a touchpower circuit.

The circuit elements in the display device 100 may be defined as acombination of all or some circuit elements which are conceptuallyseparated from each other. For example, a power circuit (not shown) maybe defined as a circuit including the entire or a part of the powermanagement IC 123 and including another circuit element.

FIG. 2 illustrates, from the viewpoint of a power circuit, theconfiguration of a touch sensing circuit according to an embodiment ofthe present disclosure.

Referring to FIG. 2 , the power management IC 123 may include a firstpower circuit 123-1, a second power circuit 123-2, a third power circuit123-3, a fourth power circuit 123-4, etc.

The power management IC 123 may be subdivided based on functions, andthe power management IC 123 may include multiple power circuits 123-1 to123-4 therein. The multiple power circuits 123-1 to 123-4 may receivemain power or sub-power to generate power, and may supply the power tocircuits in the display device 100. Voltages, which the multiple powercircuits 123-1 to 123-4 generate in order to supply power, may beseparately defined as a first driving voltage, a second driving voltage,a third driving voltage, a fourth driving voltage, etc.

Some of the multiple power circuits 123-1 to 123-4 may drive a coupledcircuit formed by integrating a display circuit and a touch circuittogether. The display circuit may include a circuit which involves in adisplay operation of outputting image data through pixels by the displaydevice 100, and the touch circuit may include a circuit which involvesin a touch operation of sensing touching or approaching of an externalobject by the display device 100 through a touch electrode.

For example, the display circuit may include a gamma circuit 170 forgenerating a gamma voltage corresponding to a greyscale value in orderto generate a data voltage corresponding to image data (RGB), a sourcedriver IC which is included in a source readout IC 120 and outputs adata voltage, and a timing controller 150 for controlling a sourcedriver and supplying image data (RGB). The touch circuit may include atouch modulation IC 121, which generates a touch driving voltage(VCOM_M) for driving a touch electrode, and a microcontroller 122, whichcontrols a readout IC included in the source readout IC 120 and receivestouch data to calculate touch coordinates.

The display circuit and the touch circuit may involve in one of adisplay operation and a touch sensing operation, but the coupled circuitmay involve in both the display operation and the touch sensingoperation. The coupled circuit may have a form in which the displaycircuit and the touch circuit are integrated together. For example, thecoupled circuit may include a source readout integrated circuit (SRIC)120 in which the source driver IC and the readout IC are integratedtogether.

The first power circuit 123-1 may generate a display analog voltage(AVDD_D) to drive the source readout IC 120. The first power circuit123-1 may generate an analog voltage (Analog VDD (AVDD)) to supplypower, and, in particular, may generate an analog voltage from a mainvoltage (V_D). The display analog voltage (AVDD_D) may imply an analogvoltage generated based on the main voltage (V_D). As necessary, theanalog voltage (Analog VDD (AVDD)) generated by the first power circuit123-1 may be defined as a first voltage.

The first power circuit 123-1 may generate a common voltage (VCOM) todrive the touch modulation IC 121. The touch modulation IC 121 maygenerate, from the common voltage (VCOM), the touch driving voltage(VCOM_M) for driving a touch electrode. A touch modulation IC 121 maytransfer the touch driving voltage (VCOM_M) to the source readout IC120.

The second power circuit 123-2 may convert power received from a host160 and may supply the power to the microcontroller 122. The secondpower circuit 123-2 may include a step-down converter or a buckconverter (BUCK), which converts an output voltage into a voltage thatis lower than an input voltage. For example, the second power circuit123-2 may receive a signal having a 5V voltage of sub-power and mayconvert the signal into a signal having another voltage such as 1.8V or3.3V. The second power circuit 123-2 may transmit the converted voltageto a microcontroller (microcontroller unit (MCU)) 122.

The third power circuit 123-3 may convert power received from the host160 to supply the power to the gamma circuit 170. The third powercircuit 123-3 may include a buck converter (BUCK). The third powercircuit 123-3 may convert the main voltage (V_D) from the host 160, andmay drive the gamma circuit 170 through the converted voltage.

The fourth power circuit 123-4 may convert power received from the host160 to supply the power to the timing controller 150. The fourth powercircuit 123-4 may include a buck converter (BUCK). The fourth powercircuit 123-4 may convert the main voltage (V_D) from the host 160 andmay drive the timing controller 150 through the converted voltage.

The source readout IC 120 may operate through a driving voltagetransferred from the first power circuit 123-1. The source readout IC120 may receive the display analog voltage (AVDD_D) to operate internalcircuits. The source driver IC and the readout IC, which are integratedtogether in the source readout IC 120, may operate by using the displayanalog voltage (AVDD_D) as power.

The touch modulation IC 121 may provide a driving voltage to the sourcereadout IC 120. The touch modulation IC 121 may receive the commonvoltage (VCOM) from the first power circuit 123-1 to generate the touchdriving voltage (VCOM_M) for driving a touch electrode. Further, thetouch modulation IC 121 may receive a gate low voltage (VGL) and a gatehigh voltage (VGH) from a power circuit (not shown) to generate amodulation gate low voltage (VGL_M) applied to the touch electrode.

The timing controller 150 may operate using power supplied from thefourth power circuit 123-4. The timing controller 150 may transmit acontrol signal (DCS) and image data (RGB) to control the source readoutIC 120.

The gamma circuit 170 may generate a gamma voltage by using powersupplied from the third power circuit 123-3. Further, the gamma circuit170 may receive the display analog voltage (AVDD_D) from the first powercircuit 123-1. An amplifier of the gamma circuit 170 may receive,through an input terminal, a voltage applied from the third powercircuit 123-3, and may receive the display analog voltage (AVDD_D)through a bias terminal. The amplifier may generate a gamma voltage fromthe voltage of the third power circuit 123-3 and the display analogvoltage (AVDD_D).

The host 160 may supply a main power or a sub-power to the powermanagement IC 123 through a power line, and each power may betransferred to the multiple power circuits 123-1 to 123-4 in the powermanagement IC 123. If the host 160 can supply power through aninterface, the type thereof is not limited.

For example, the main voltage (V_D) may be provided to the first powercircuit 123-1, the third power circuit 123-3 and the fourth powercircuit 123-4 through a first power line, and a sub-voltage (V_T) may beprovided to the second power circuit 123-2 through the second powerline. Further, the first power circuit 123-1, the third power circuit123-3, and the fourth power circuit 123-4 may convert the input mainpower to generate various types of power signals. The second powercircuit 123-2 may convert the input sub-power to generate various typesof power signals.

The display device 100 may operate in a normal mode, a display mode, ora sleep mode. The normal mode may be defined as a mode in which thedisplay device 100 performs both display driving and touch driving, thedisplay mode may be defined as a mode in which the display device 100performs only display driving without performing touch driving, and thesleep mode may be defined as a mode in which the display device 100performs only touch sensing without performing display driving. In thenormal mode among the operation modes of the display device, both thedisplay circuit and the touch circuit may operate. In the display mode,the touch circuit may not operate and only the display circuit mayoperate. In the sleep mode, the display circuit may not operate and onlythe touch circuit may operate.

Each driving mode of the display device may be implemented so as toblock supply of power transferred to the display circuit and the touchcircuit. For example, in the normal mode, the host 160 may provide boththe main voltage (V_D) and the sub-voltage (V_T). In the display mode,the host 160 may provide only the main voltage (V_D). In the sleep mode,the host 160 may provide only the sub-voltage (V_T).

When the main voltage (V_D) and the sub-voltage (V_T) are separatelysupplied based on each driving mode of the display device, a coupledcircuit including both the display circuit and the touch circuit is notsupplied with appropriate power. In particular, when the coupled circuitis supplied with only one input voltage as a source, and when thissource voltage is blocked according to a mode, an operation of a partialcircuit of the coupled circuit is limited.

For example, the source readout IC 120 including the source driver ICand the readout IC may be supplied with only the display analog voltage(AVDD_D) based on the main voltage (V_D) as power from only the firstpower circuit 123-1. If the display device 100 operates in the sleepmode, the main voltage (V_D) is blocked, and thus the circuits driven bythe main voltage (V_D) may be turned off. The circuits to be turned offare a display circuit such as the timing controller 150 and the gammacircuit 170, and a circuit for supplying power to the display circuit,such as the first power circuit 123-1, but the coupled circuit includingthe display circuit and the touch circuit may be also turned off. Then,the readout IC may not be supplied with power even when needing toperform touch driving in the sleep mode, and thus touch sensing in thesleep mode may not be properly performed.

The power management IC 123 according to an embodiment may be maintainedsuch that touch sensing can be performed regardless of each driving modeof the display device, and may change internal circuit elements orinclude a separate circuit element so as to reduce the amount of powerused.

FIG. 3 is a first illustrative block diagram showing a signal flow of atouch sensing circuit according to an embodiment of the presentdisclosure.

Referring to FIG. 3 , a display device 200 may include a source readoutIC 220, a touch modulation IC 221, a microcontroller 222, a first powercircuit 223, a second power circuit 224, a multiplexer 225, a gatedriving circuit 230, a level shifter 231, the timing controller 250,etc.

The source readout IC 220, the touch modulation IC 221, themicrocontroller 222, the first power circuit 223, the second powercircuit 224, the multiplexer 225, the gate driving circuit 230, thelevel shifter 231, and the timing controller 250 may include theabove-described circuit configurations and functions in FIGS. 1 and 2 ,and may include even embodiments that can be changed by those skilled inthe art.

The multiplexer 225 may receive a first voltage, for example, a mainvoltage (V_D), transferred through a first power line, and may receive asecond voltage, for example, a sub-voltage (V_T), transferred through asecond power line. The first voltage and the second voltage may bevoltages having the same magnitude, but voltages having differentmagnitudes may be transferred to the multiplexer 225 as necessary.

The multiplexer 225 may select and output one of multiple analog signalswhich are input, and whether to operate, operation timing, the type of aselected and output signal, etc. may be controlled by a control signalfrom the timing controller 250 or the microcontroller 222.

Further, as necessary, the multiplexer 225 may determine a signal, whichis to be selected and output, on the basis of the types and the numberof input signals without receiving a separate control signal from theoutside through an internal calculation device (not shown). For example,the internal calculation device (not shown) may configure a reference soas to select and output the first voltage when both the first voltageand the second voltage are transferred to the multiplexer 225, and mayadditionally perform a calculation for determining the type of an inputsignal in consideration of the intensity of the input signal, the timingthereof, the position of an input port, or the like when one of thefirst voltage or the second voltage is transferred.

Further, the multiplexer 225 may also determine an output signal on thebasis of a predefined reference, for example, whether main power orsub-power is input, without performing a separate calculation.

The multiplexer 225 may differently change the selected type of voltagedepending on driving modes of a panel. The driving modes of the panelmay be divided into a normal mode, a display mode, and a sleep mode. Inthe normal mode, both the main power and the sub-power may be input intothe multiplexer 225. In the display mode, the main power may be inputinto the multiplexer 225 but the sub-power may not be input thereinto.In the sleep mode, the sub-power may be input into the multiplexer 225but the main power may not be input thereinto.

For example, when both the main power and the sub-power are input intothe multiplexer 225, the multiplexer 225 or a switch circuit in themultiplexer 225 may select one type of power therefrom. In order to morestably supply power, the multiplexer 225 may first select the main powerand may transfer the same to the first power circuit 223 connectedthereto. In this case, display driving may be performed through thefirst power circuit 223, and touch driving may be performed through thesecond power circuit 224. The second power circuit 224 may be connectedthrough the second power line connected to an input terminal of themultiplexer 225, and thus power can be stably supplied without beingaffected by whether display driving is performed.

In another example, when only the main power is input into themultiplexer 225, the multiplexer 225 or the switch circuit in themultiplexer 225 may transfer the main power to the first power circuit223. In this case, the main power may be transferred to the first powercircuit 223, and only a display operation may be performed. Further,since the sub-power is not transferred to the second power circuit 224and a line for transferring the sub-power is separated from a line fortransferring the main power, the display device may not perform a touchoperation.

In another example, when only the sub-power is input into themultiplexer 225, the multiplexer 225 or the switch circuit in themultiplexer 225 may transfer the sub-power to the first power circuit223. In this case, the sub-power is transferred to the first powercircuit 223, and thus power may be supplied to the touch modulation IC221 and the source readout IC 220. Further, the sub-power is transferredto the second power circuit 224, and thus a touch operation may beperformed. A display circuit and a touch circuit may remain in aconnected state without separating from each other such that thesub-power can be transferred to the first power circuit 223.

When the main power and the sub-power are transferred to the first powercircuit 223 through the multiplexer 225, the continuity of power supplycan be maintained, and it is possible to solve a problem of instabilityof power supply caused by separation between power supplied to the touchcircuit and power supplied to the display circuit and a problem ofexcess supply of power caused by nonsepartion therebetween in theconventional touch sensing circuit.

Further, multiple types of input power may be easily output by only anoperation of the multiplexer 225, and thus power consumption forcalculation by the microcontroller 222 and the timing controller 250 maybe reduced.

The first power circuit 223 may separately recognize the main voltage(V_D) and the sub-voltage (V_T), and may sense and determine whether themain voltage (V_D) supplied through the first power line is in an ONstate or an OFF state. For example, when the main voltage (V_D) and thesub-voltage (V_T) are supplied as voltages having the same magnitude,the first power circuit 223 may form a separate sensing line between thefirst power circuit 223 and the first power line in order to determinewhich voltage is the main voltage (V_D).

The first power circuit 223 may include an inner circuit element capableof performing calculation in order to determine the state of the mainvoltage (V_D), for example, the magnitude of the main voltage (V_D),whether there is an input, input timing, a signal waveform, etc.

When the main power is in an ON state, the first power circuit 223 maytransfer a driving voltage to the gate driving circuit 230, the levelshifter 231, the timing controller 250, the source readout IC 220, andthe touch modulation IC 221, and may divide the driving voltage into afirst driving voltage or a second driving voltage based on a target of avoltage transferred to each circuit element to selectively control anoperation. For example, the first driving voltage may be a drivingvoltage that is transferred to at least one of the gate driving circuit230, the level shifter 231, and the timing controller 250, and thesecond driving voltage may be a driving voltage that is transferred toat least one of the source readout IC 220 and the touch modulation IC221. When the main power is in an OFF state, the first power circuit 223may turn off (OFF) power, for example, the first driving voltage,transferred to the gate driving circuit 230, the level shifter 231, andthe timing controller 250, thereby reducing the amount of power used. Inthis case, the first power circuit 223 may supply power, for example,the second driving voltage, only to the source readout IC 220 and thetouch modulation IC 221, thereby reducing the amount of power used. Thefirst power circuit 223 may change an operation so as to sense theON/OFF state of the main power and output driving signals havingdifferent signal levels, and thus may effectively reduce the amount ofpower used for touch driving.

When the main power of the first power circuit 223 is an ON state, adisplay screen may be stably transmitted regardless of whether thesub-power is input. The display screen may not be transmitted only whenthe main power is an OFF state.

The first driving voltage and the second driving voltage refer todriving voltages transferred from the first power circuit 223, and thetype of a driving voltage may be defined based on a target to which avoltage is transferred, or may be defined based on timing at which avoltage is transferred.

The driving voltage of the first power circuit 223 may be controlled bythe internal calculation device (not shown), or may be controlled by themicrocontroller 222. Further, the state of a driving voltage generatedby the first power circuit 223 may be differently defined depending onconditions stored in an internal memory (not shown). For example, areference stored in the memory (not shown) may be a reference forchanging the size or waveform of a driving voltage, and may be areference for determining the on/off state of a driving voltage.

Both or one of the first driving voltage and the second driving voltagemay be transferred from the first power circuit 223 at the same time orat different times, and the order or method of supply of a drivingvoltage based on an operation of the first power circuit 223 accordingto the calculation result may be defined in a scheme different from theabove scheme. The second power circuit 224 may supply power to themicrocontroller 222 in order to maintain a touch operation. In order toreduce the amount of power consumed by the microcontroller 222, thesecond power circuit 224 may include at least on buck converter. Asub-voltage input by the buck converter may be changed into a lowervoltage, and may be maintained as a voltage suitable for driving of themicrocontroller 222.

The second power circuit 224 may directly receive the sub-power throughthe second power line which is connected to an input terminal of themultiplexer but not to an output terminal thereof. Therefore, it ispossible to prevent power loss caused by bypass supply via themultiplexer 225 and the first power circuit 223. Further, power, whichthe first power circuit 223 supplies to the display circuit, and power,which the second power circuit 224 supplies to the touch circuit, may beindependently managed and controlled.

In an In-Cell scheme in which a touch operation and a display operationare implemented by one panel, the touch operation and the displayoperation are not electrically disconnected from each other and sharecircuit elements. Therefore, the power circuit according to anembodiment may electrically disconnect the first power circuit from thesecond power circuit, and may thus stably implement the touch operationand the display operation.

When both the main voltage and the sub-voltage are input into themultiplexer 225, the microcontroller 222 or the timing controller 250may generate a control signal for selecting and outputting the mainvoltage and may transfer the control signal to the multiplexer 225.

The microcontroller 222 may generate a control signal for adjusting anoutput voltage of the first power circuit 223, and may transfer thecontrol signal to the first power circuit 223.

The touch modulation IC 221 may receive an output voltage of the firstpower circuit, and may synchronize and modulate, during a touch drivingperiod, a voltage transferred to the source readout IC 220 and a voltagetransferred to the level shifter 231 connected to the gate drivingcircuit 230. Operation of the source readout IC 220 and the gate drivingcircuit 230 may be performed at the same time or in conjunction witheach other so as to have a predetermined temporal connectionrelationship therebetween.

Meanwhile, the multiplexer can be omitted. FIG. 9 is a thirdillustrative block diagram showing a signal flow of a touch sensingcircuit according to an embodiment of the present disclosure.

As shown in FIG. 9 , the first power line for supplying the main power(or main voltage) (V_D) can be connected to the first power circuit 223,and the second power line for supplying the sub-power (or sub-voltage)(V_T) can be connected to the first power circuit 223 and the secondpower circuit 224. As described above, the driving mode of the panel canbe divided into a normal mode, a display mode, and a sleep mode.

As an example, when driven in the normal mode, the main voltage (V_D)can be input to the first power circuit 223 through the first powerline, and the sub-voltage (V_T) may be input to the first power circuit223 and the second power circuit 224 through the second power line.Therefore, the first power circuit 223 can generate driving voltages fordriving the timing controller 250, the level shifter 231, the touchmodulation circuit 221, the source readout circuit 220, etc. based onthe main voltage (V_D) and the sub-voltage (V_T), and the second powercircuit 224 can generate a driving voltage for driving themicrocontroller 222 based on the sub-voltage (V_T). Accordingly, thedisplay operation and the touch sensing operation can be performed.

As another example, when driven in the display mode, the main voltage(V_D) is input to the first power circuit 223 through the first powerline, but the sub-voltage (V_T) may not input to the first power circuit223 and the second power circuit 224 through the second power line. Thefirst power circuit 223 can generate driving voltages for a displayoperation based on the main voltage (V_D), but the second power circuit224 may not generate a driving voltage for a touch sensing operation.Accordingly, only the display operation can be performed.

As another example, when driven in sleep mode, the main voltage (V_D)can be input to the first power circuit 223 through the first powerline, and the sub-voltage (V_T) may be input to the first power circuit223 and the second power circuit 224 through the second power line. Thefirst power circuit 223 can generate driving voltages for a touchsensing operation without generating driving voltages for a displayoperation based on the sub-voltage (V_T). The second power circuit 224can generate a driving voltage for a touch sensing operation based onthe sub-voltage (V_T). Accordingly, only the touch sensing operation canbe performed.

FIG. 4 is a second illustrative block diagram showing a signal flow of atouch sensing circuit according to an embodiment of the presentdisclosure.

Referring to FIG. 4 , the first power circuit 223 and the second powercircuit 224, described above, may be integrated to form one powermanagement IC 226.

The touch operation control implemented in the second power circuit 224in FIG. 3 may be implemented through a logic circuit in the powermanagement IC 226.

The power management IC 226 may sense, using an internal calculationprocessing circuit, whether the main voltage (V_D) and the sub-voltage(V_T), aside from a control signal of the microcontroller 222, areinput, and, when only the main voltage (V_D) is input, may drive asource readout IC 220, a touch modulation IC 221, a gate driving circuit230, a level shifter 231, or a timing controller 250 to perform adisplay operation. Further, the one integrated power management IC 226may transfer a voltage for driving the microcontroller 222, therebyperforming a touch operation too. When both the main voltage (V_D) andthe sub-voltage (V_T) are input, the multiplexer 225 may configurepriority as supplying the main voltage (V_D) to the power management IC226. The timing controller 250 may transfer information about thedriving mode of panel to the multiplexer 225 for each time interval tochange an output depending on an operation of the power management IC226.

When only the sub-voltage (V_T) is input, the multiplexer 225 may outputthe sub-voltage (V_T) and may supply the same to the power management IC226, and the power management IC 226 may sense that the main power (V_D)is OFF, and may change power of the gate driving circuit 230, the levelshifter 231, or the timing controller 250 to OFF or may maintain thepower thereof. The power management IC 226 may change power of thesource readout IC 220, the touch modulation IC 221, or themicrocontroller 222 to ON or may maintain the power thereof. A totalpower consumption of the display device 200 may be reduced bymaintaining display-related circuits in an OFF state.

FIG. 5 is a timing diagram illustrating a change in input power of apower management IC according to an embodiment of the presentdisclosure.

Referring to FIG. 5 , the type of power transferred to the powermanagement IC may be changed depending on each time interval.

In order to select one from among multiple types of input powertransferred from an external system, a multiplexer (not shown) may beconnected to the front end of a power management IC (not shown), and, ina first time interval t1, a main voltage (V_D) may be transferred.

The power management IC (not shown) or a touch control circuit (notshown) may monitor the type of input power for each time interval, andmay maintain the state of a previous time interval when input power isnot changed. If the state of input power to be monitored, for example,the main power, is changed, the multiplexer (not shown) may change inputpower transferred to the power management IC.

In a second time interval t2, a sub-voltage (V_T) may be selected as anoutput voltage of the multiplexer (not shown) and may be transferred tothe power management IC. As in the first time interval t1, input powermay also be monitored in the second time interval (t2).

In a third time interval t3, the main voltage (V_D) may be selected asan output voltage of the multiplexer (not shown) and may be transferredto the power management IC.

During the first time interval t1 to the third time interval t3, inrelation to an operation of the multiplexer, the above-describedoperation of the multiplexer in FIGS. 1 to 4 may be performed.

FIG. 6 is a diagram illustrating a method for determining an operationmode of a panel according to an embodiment of the present disclosure.

Referring to FIG. 6 , a method 1000 for determining the operation modeof a panel may include a step (S1001) of determining the type of powerinput, a step (S1003) of determining whether to perform display driving,a step (S1005) of determining whether to perform touch driving, a step(S1007) of determining the driving mode of a panel, or the like, and theorder of the steps may be changed.

In the step (S1001) of determining the type of power input, the type andthe state (for example, the intensity of a voltage and a current) ofpower transferred to a power management IC (not shown) or a multiplexer(not shown) may be determined. For example, the power management IC (notshown) may determine whether a first voltage transferred through a firstpower line is input.

In the step (S1003) of determining whether to perform display driving,whether to perform display driving may be determined based on the typeand the state (for example, the intensity of a voltage and a current) ofpower transferred to the power management IC (not shown) or themultiplexer (not shown). The power management IC (not shown) maydifferently configure whether to perform display driving, depending onwhen only main power is input, when only sub-power is input, or when themain power and the sub-power are simultaneously input. For example, whenthe main power is transferred to the power management IC (not shown) orthe multiplexer (not shown), display driving may be performed.

In the step (S1005) of determining whether to perform touch driving,whether to perform touch driving may be determined by determiningwhether the sub-power is input. The power management IC (not shown) mayperform touch driving when the sub-power is input.

In the step (S1007) of determining the driving mode of a panel, thedriving mode of a panel, for example, a normal mode, a display mode, ora sleep mode, may be configured based on the type and state of powertransferred to the power management IC (not shown) or the multiplexer(not shown). The driving mode of a panel may be defined based on thetype of input power. However, conversely, the type of input power may bedifferently adjusted based on the driving mode of a panel.

FIG. 7 is a diagram illustrating a method for determining an operationof a power management IC according to an embodiment of the presentdisclosure.

Referring to FIG. 7 , a method 1100 for determining an operation of apower management IC may include a step (S1101) of determining the typeof power input, a step (S1103) of generating a multiplexer controlsignal, a step (S1105) of selecting input power of the power managementIC, a step (S1107) of driving the power management IC, etc.

The step (S1101) of determining the type of power input may be a step ofdetermining the type of power input into a multiplexer (not shown), forexample, main power and sub-power.

The step (S1103) of generating a multiplexer control signal may be astep of generating a signal for controlling an operation of themultiplexer by a microcontroller (not shown) or a timing controller (notshown).

The step (S1105) of selecting input power of the power management IC maybe a step of controlling an output voltage of the multiplexer on thebasis of the above-described signal for controlling an operation of themultiplexer by the microcontroller (not shown) or the timing controller(not shown), and transferring the output voltage to the power managementIC.

The step (S1107) of driving the power management IC may be a step ofdriving the power management IC by turning on (ON) or turning off (OFF)power input into a source readout IC, a touch modulation IC, a levelshifter, a timing controller, a microcontroller, etc. which areconnected based on the type and state of input power, or by changing thephase of a voltage or timing.

FIG. 8 is a diagram illustrating a method for dividing an operation modeof a panel according to an embodiment of the present disclosure.

Referring to FIG. 8 , a method 1200 for dividing the driving mode of apanel may include a step (S1201) of receiving input power, a step(S1202) of determining whether main power is input, a step (S1203) ofdetermining whether sub-power is input, etc., and may be a calculationperformed in a touch power circuit (not shown) or a microcontroller (notshown).

The step (S1201) of receiving input power may be a step of receivingmultiple types input power through multiple power lines. At least onebuck circuit, at least one power management IC, and at least onemultiplexer may be connected in sequence or in parallel to receive inputpower.

The step (S1202) of determining whether main power is input may be astep of determining whether there is main power transferred to the powermanagement IC (not shown) or the multiplexer (not shown) and, when themain power is not input, configuring the driving mode of a panel as asleep mode.

The step (S1203) of determining whether sub-power is input may be a stepof determining whether there is sub-power transferred to the powermanagement IC (not shown) or the multiplexer (not shown) and, when thesub-power is not input, configuring the driving mode of a panel as adisplay mode. If the sub-power is input, the driving mode of a panel maybe determined to be a normal mode.

The step (S1203) of determining whether sub-power is input may be a stepof performing determination only when the main power is input. However,the order of determining whether the main power is input and determiningwhether the sub-power is input is not limited thereto.

In a display mode (S1204), in relation to operation of the panel, onlydisplay operation may be performed but a touch operation may not beperformed.

In a normal mode (S1205), in relation to operation of the panel, boththe display operation and the touch operation may be performed.

In a sleep mode (S1206), in relation to operation of the panel, onlytouch operation may be performed but the display operation may not beperformed.

Information about the display mode (S1204), the normal mode (S1205), andthe sleep mode (S1206) may be stored in a microcontroller (not shown) ora timing controller (not shown), and may be used to control an operationof each circuit or to control a power input operation.

What is claimed is:
 1. A power circuit comprising: a first power linefor supplying a first voltage; a second power line for supplying asecond voltage; a first power circuit connected to the first power lineand the second power line and; and a second power circuit connected tothe second power line, wherein a driving mode of a panel comprises anormal mode, a display mode and a sleep mode, wherein the first voltageis input into the first power circuit through the first power line andthe second voltage is input into the first power circuit and the secondpower circuit through the second power line in the normal mode, whereinthe first voltage is input into the first power circuit through thefirst power line but the second voltage is not input into the firstpower circuit and the second power circuit through the second power linein the display mode, and wherein the first voltage is input into thefirst power circuit through the first power line and the second voltageis input into the first power circuit and the second power circuitthrough the second power line in the sleep mode.
 2. The power circuit ofclaim 1, wherein the second power circuit comprises a buck converterconfigured to change an output voltage to be lower than the firstvoltage or the second voltage.
 3. The power circuit of claim 1, whereinthe first power circuit is configured to transfer a display drivingvoltage to a source readout circuit when the first voltage is input. 4.The power circuit of claim 3, wherein the first power circuit isconfigured to transfer a touch driving voltage having a magnitudedifferent from that of the display driving voltage to a source readoutcircuit when the second voltage is input.
 5. The power circuit of claim1, further comprising a touch modulation circuit configured to receivean output voltage of the first power circuit and synchronize tomodulate, during a touch driving period, a voltage transferred to thesource readout circuit and a voltage transferred to a level shifterconnected to a gate driving circuit.
 6. A touch sensing circuitcomprising: a first line for supplying a main voltage; a second line forsupplying a sub-voltage; a power management circuit connected to thefirst line and the second line and; a touch modulation circuit connectedto the power management circuit to modulate a signal transferred to atouch electrode on a panel; and a buck converter connected to the secondline and configured to step down the level of the sub-voltage, and totransfer the stepped-down sub-voltage to a microcontroller, wherein thedriving mode of the panel comprises a normal mode, a display mode and asleep mode, wherein the main voltage is input into the power managementcircuit through the first line and the sub-voltage is input into thepower management circuit and the buck converter through the second linein the normal mode, wherein the main voltage is input into the powermanagement circuit through the first line but the sub-voltage is notinput into the power management circuit and the buck converter throughthe second line in the display mode, and wherein the main voltage isinput into the power management circuit through the first line and thesub-voltage is input into the power management circuit and the buckconverter through the second line in the sleep mode.
 7. The touchsensing circuit of claim 6, further comprising a level shifterconfigured to receive a voltage from the touch modulation circuit or thepower management circuit and to adjust the level of a voltagetransferred to the gate driving circuit.
 8. The touch sensing circuit ofclaim 6, further comprising a touch control circuit connected to thepower management circuit and configured to control an operation of thepower management circuit.
 9. The touch sensing circuit of claim 6,wherein the power management circuit is configured to determine whetherthe main power or the sub-power is input, and transfer a common voltagefor inducing a display operation to a source readout circuit when themain power is input, and transfer a touch driving voltage for inducing atouch operation to the source readout circuit when the sub-power isinput.
 10. A touch sensing circuit comprising: a first power line forsupplying a main power; a second power line for supplying a sub-power;at least one buck converter connected to the second power line toreceive a sub-power and configured to convert an output voltage to havea level lower than that of an input voltage; and at least one powermanagement circuit connected to the first power line and the secondpower line and configured to generate a voltage and to transfer thevoltage to a source readout circuit or a touch modulation circuit,wherein a driving mode of a panel comprises a normal mode, a displaymode and a sleep mode, wherein the main power is input into the powermanagement circuit through the first power line and the sub-power isinput into the power management circuit and the buck converter throughthe second power line in the normal mode, wherein the main power isinput into the power management circuit through the first power line butthe sub-power is not input into the power management circuit and thebuck converter through the second power line in the display mode, andwherein the main power is input into the power management circuitthrough the first power line and the sub-power is input into the powermanagement circuit and the buck converter through the second power linein the sleep mode.
 11. The touch sensing circuit of claim 10, whereinthe at least one buck converter is configured to receive one of themultiple types of input power to generate and transfer a driving voltagefor a touch control circuit.
 12. The touch sensing circuit of claim 10further comprising a timing controller connected to the power managementcircuit to transfer to the power management circuit information about adriving mode of a panel for each time interval.
 13. The touch sensingcircuit of claim 10, wherein the power management circuit is configuredto supply power to the source readout circuit and to the touchmodulation circuit when the main power among input power is input. 14.The touch sensing circuit of claim 10, wherein the power managementcircuit is configured to output a voltage for display driving when themain power is input and to output a voltage for touch driving when thesub-power is input.